1. Field of the Invention
This invention relates to anti- bacterial materials, and, more particularly, to three-dimensional solid systems suitable for disinfecting water and other liquids.
2. Description of the Prior Art
The preparation of demand-type broad-spectrum resin-polyiodide water disinfectants have been described in the prior art. Such triiodide-quaternary ammonium resin disinfectants have received primary consideration since the iodine is claimed to be tenaciously bound to the active sites of the resin and is released almost entirely on a demand action basis. U.S. Pat. Nos. 3,817,860; 3,923,665 and 4,238,477.
Prior to the present invention, however, these disinfectant systems were limited in their anti-bacterial activity by the available triiodide contained therein. Furthermore such systems are not known to exhibit any algicidal activity while in use in water purification systems.
The prior art in this field was concentrated mainly in two areas. U.S. Pat. Nos. 3,817,860 and 3,923,665 describes the use of commercially available strongly basic anion exchange resins whereby the chloride ion is exchanged for an I.sub.3.sup.- ion. The triiodide modified ion exchange resin functions as a disinfectant for bacteria containing water in the form of the column of the crosslinked polymer beads through which the water is passed.
The acidic cation exchange resins which are operable are Rohm & Haas macroreticular Amberlyst ion exchange resins e.g. Amberlyst 15, Amberlyst XN-1010, Amberlite 200, Amberlite 252, Duolite C-26, Duolite C291, Amberlite IRC-50, Amberlite IRC-72 and Amberlite PP1. Other manufacturers offer similar products. These resins all have ion exchange groups and are supplied in the salt form, usually as the sodium or hydrogen, and as porous granular or beads of various mesh sizes.
Conventional ion exchange resins are essentially homogeneous crosslinked gels where the pore structure is the distance between polymeric chains. This type of molecular porosity is considered as microporous of microreticular. Macroreticular resins, in contrast, contain significant nongel porosity in addition to the normal gel porosity.
U.S. Pat. No. 4,238,477 describes a process to prepare resin-polyiodide disinfecting materials in a controlled and homogeneous manner. This process consists of converting the X.sup.- anion to the iodide form (I.sup.-) followed by premeasuring an equivalent weight of iodine (I.sub.2) needed to prepare the poly-iodide of choice, usually (I.sub.3.sup.31) , dissolving the (I.sub.2) in water, and continuously circulating the solution until the conversion is complete.
U.S. Pat. No. 4,420,590 expanded on this technology in that strongly basic anion-exchange resins with anion counter-ions were replaced with controlled relative proportion of iodide-bromide polyhalides.
This invention differs significantly from the prior art in that the germicidal activity is due entirely to the very strongly bound silane quaternary to either a carboxylate or sulfonate anionic site on the ion exchange resin. All other germicidal contact ion exchange resins depended on the presence of a halide, interhalide or intrahalide electrostatically bound to the resin as the activity site for the destruction of bacteria.
Silane quaternaries bonded to water-insoluble substrates has been shown to kill various type of bacteria. The first published report of this phenomenon was by Walters, Abbot and Isquith, Applied Microbiology, Feb., 1973, pgs. 253-256. Subsequent U.S. patents by these investigators, U.S. Pat. Nos. 3,730,701 and 3,794,736 disclosed suitable silane quaternaries operable as bound disinfecting contact germicides. A more recent U.S. Pat. No. 4,259,103, describes the overall procedure required to achieve such germicidal properties. More particularly, the process involves contacting a substrate, where ammonium, phosphonium or sulfonium cationic ions are present, with a silane quaternary having a hydrolyzable group attached to the silicon atom.
The prior art, however does not disclose or teach the preparation of an enhanced water disinfecting system by reacting a silane quaternary salt with a weak or strong cationic macroreticular ion exchange resin to form powerful and effective disinfecting systems.
Accordingly, it is an object of the present invention to provide a new and improved three-dimensional water contact disinfectant system which has a strong anti-bacterial effect with no leaching of any chemical substance.
Another object herein is to provide such a water disinfectant which has broad spectrum anti-bacterial activity including gram-positive, gram-negative and algicidal activity.
Still another object herein is to provide a three-dimensional water disinfectant which is a cross-linked organo-silicon quaternary ammonium salt attached to a macroreticular ion exchange resin.
Yet another object of the invention is to provide methods for preparing three dimensional water disinfecting system.